CVE-2018-3836 in Leptonica
Summary
by MITRE
An exploitable command injection vulnerability exists in the gplotMakeOutput function of Leptonica 1.74.4. A specially crafted gplot rootname argument can cause a command injection resulting in arbitrary code execution. An attacker can provide a malicious path as input to an application that passes attacker data to this function to trigger this vulnerability.
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Analysis
by VulDB Data Team • 03/07/2023
The vulnerability identified as CVE-2018-3836 represents a critical command injection flaw within Leptonica version 1.74.4, specifically within the gplotMakeOutput function. This issue arises from insufficient input validation and sanitization when processing user-supplied data, creating a pathway for malicious actors to execute arbitrary code on affected systems. The vulnerability manifests when an application utilizing Leptonica processes a specially crafted gplot rootname argument, which is then passed directly to system commands without proper sanitization.
The technical exploitation of this vulnerability occurs through the improper handling of user input within the gplotMakeOutput function, which serves as a plotting utility within the Leptonica library. When an attacker provides a malicious rootname argument containing shell metacharacters or command injection sequences, the function fails to properly escape or validate these inputs before incorporating them into system command execution contexts. This design flaw directly maps to CWE-78, which specifically addresses OS command injection vulnerabilities where untrusted data is concatenated or interpolated into shell commands without proper sanitization. The vulnerability demonstrates a classic improper input validation issue that allows attackers to manipulate the execution flow of the application.
The operational impact of CVE-2018-3836 extends beyond simple code execution, as it provides attackers with potential full system compromise capabilities. Since the vulnerability allows arbitrary code execution, an attacker could potentially escalate privileges, install backdoors, or exfiltrate sensitive data from systems running affected versions of Leptonica. The attack vector is particularly concerning because it can be triggered through legitimate application interfaces that process user-provided data, making it difficult to detect and prevent through traditional network monitoring approaches. This vulnerability affects any application that relies on Leptonica 1.74.4 for image processing and plotting functionalities, including document processing systems, image analysis tools, and various software applications that utilize the library for graphical output generation.
Mitigation strategies for CVE-2018-3836 should focus on immediate remediation through version upgrading to Leptonica 1.75.0 or later, where the command injection vulnerability has been addressed through proper input validation and sanitization. Organizations should implement comprehensive input validation measures that prevent shell metacharacters from being processed within the gplotMakeOutput function, including the use of allow-list validation for rootname arguments. Additionally, the implementation of proper command execution practices such as using parameterized commands rather than string concatenation can significantly reduce the risk of exploitation. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving command and script injection, specifically T1059.001 for command shell injection, and T1068 for exploit for privilege escalation. Organizations should also consider implementing network segmentation and monitoring to detect unusual command execution patterns that might indicate exploitation attempts, while maintaining regular security updates and vulnerability assessments to prevent similar issues in other components of their software stack.